Corundum-spinel purging plugs were optimized through adjusting the formulation and the particle size composition of starting materials to prolong the service life of purging plugs for a 60 t refining ladle in a steel plant. The optimized formulation is 30 mass% tabular corundum (6-3 mm), 20 mass% tabular corundum (3-1 mm), 22 mass% tabular corundum (1-0.5 mm) + sintered spinel, 28% tabular corundum fines (0.045 mm) + fused spinel (0.045 mm) + bimodal α-Al2O3 micropowder + Secar71 cement. The on-site results show that the plug can achieve an obviously long service life of 18 cycles, saving cost greatly.